abstract class Parser[+T] extends AnyRef
The abstract base for all parser implementations.
Contains the main parse
function as well as various
combinator function to create a new parser based on this one.
- Alphabetic
- By Inheritance
- Parser
- AnyRef
- Any
- Hide All
- Show All
- Public
- All
Instance Constructors
- new Parser()
Abstract Value Members
-
abstract
def
parse(in: SourceCursor): Parsed[T]
Parses the string content in the specified context and returns the result.
Parses the string content in the specified context and returns the result.
This is the only abstract method in
Parser
that concrete implementations need to implement.
Concrete Value Members
-
final
def
!=(arg0: Any): Boolean
- Definition Classes
- AnyRef → Any
-
final
def
##(): Int
- Definition Classes
- AnyRef → Any
-
def
*: Repeat[T]
Returns a parser that repeatedly applies this parser.
Returns a parser that repeatedly applies this parser. It will always succeed, potentially with an empty list as the result.
-
def
+: Repeat[T]
Returns a parser that repeatedly applies this parser (at least once).
-
def
<~[U](p: Parser[U]): Parser[T]
Applies the specified parser to the input left over by this parser, but only keeps the left result.
Applies the specified parser to the input left over by this parser, but only keeps the left result.
a <~ b
only succeeds if both parsers succeed. -
def
<~(value: String): Parser[T]
Attempts to parse the specified literal string from the input left over by this parser, but only keeps the left result.
Attempts to parse the specified literal string from the input left over by this parser, but only keeps the left result.
a <~ b
only succeeds if both parsers succeed. -
final
def
==(arg0: Any): Boolean
- Definition Classes
- AnyRef → Any
-
def
>>[U](fq: (T) ⇒ Parser[U]): Parser[U]
Operator synonym for
flatMap
. -
def
?: Parser[Option[T]]
Returns a parser that optionally parses what this parser parses.
-
def
^^[U](f: (T) ⇒ U): Parser[U]
A synonym for
map
, allowing the grammar to be declared in a concise way. -
def
as[U](v: ⇒ U): Parser[U]
Returns a parser that ignores the result of this parser (if it succeeds) and returns the specified result instead.
Returns a parser that ignores the result of this parser (if it succeeds) and returns the specified result instead.
Subclasses may override this method to avoid any expensive result processing.
-
final
def
asInstanceOf[T0]: T0
- Definition Classes
- Any
-
def
clone(): AnyRef
- Attributes
- protected[lang]
- Definition Classes
- AnyRef
- Annotations
- @throws( ... ) @native()
-
def
collect[U, V >: T](f: PartialFunction[T, U], error: (V) ⇒ String = ...): Parser[U]
Returns a parser that applies a partial function to the result of this parser.
Returns a parser that applies a partial function to the result of this parser.
p.collect(f)
succeeds ifp
succeeds andf
is defined at the result ofp
, In that case it returnsf
applied to the result ofp
.- f
a partial function that will be applied to this parser's result.
- error
an optional function that takes the same argument as
f
and produces an error message.
-
def
count: Parser[Int]
Returns a parser that produces the number of characters consumed by this parser while discarding the original result.
-
def
cursor: Parser[SourceFragment]
Provides a cursor over the input consumed by this parser while discarding the actual result.
Provides a cursor over the input consumed by this parser while discarding the actual result. Use
withCursor
if you also need access to the result.This is required for parsers that create AST nodes that need to be resolved in a rewrite step and need to report the source location in case of failure. It is also required when passing a result of a first-pass parser to a recursive parser to preserve line positions.
-
final
def
eq(arg0: AnyRef): Boolean
- Definition Classes
- AnyRef
-
def
equals(arg0: Any): Boolean
- Definition Classes
- AnyRef → Any
-
def
evalMap[U](f: (T) ⇒ Either[String, U]): Parser[U]
Returns a parser that applies a function to the result of this parser producing an
Either
whereLeft
is interpreted as failure.Returns a parser that applies a function to the result of this parser producing an
Either
whereLeft
is interpreted as failure. It is an alternative to^?
for scenarios where the conditional check cannot be easily performed in a pattern match.
p.evalMap(f)
succeeds ifp
succeeds andf
returns aRight
when applied to the result ofp
. -
def
finalize(): Unit
- Attributes
- protected[lang]
- Definition Classes
- AnyRef
- Annotations
- @throws( classOf[java.lang.Throwable] )
-
def
flatMap[U](f: (T) ⇒ Parser[U]): Parser[U]
Builds a new parser by applying the specified function to the result of this parser and subsequently applying the parser returned by that function to the input left over by this parser.
-
final
def
getClass(): Class[_]
- Definition Classes
- AnyRef → Any
- Annotations
- @native()
-
def
handleErrorWith[U >: T](f: (Failure) ⇒ Parser[U]): Parser[U]
Handle any error, potentially recovering from it, by mapping it to a new parser that will be applied at the same starting position than the failing parser.
Handle any error, potentially recovering from it, by mapping it to a new parser that will be applied at the same starting position than the failing parser.
This is similar to the
orElse
or|
method, but allows the alternative parser to inspect the error of the preceding one.- See also
recoverWith to recover from only certain errors.
-
def
hashCode(): Int
- Definition Classes
- AnyRef → Any
- Annotations
- @native()
-
final
def
isInstanceOf[T0]: Boolean
- Definition Classes
- Any
-
def
map[U](f: (T) ⇒ U): Parser[U]
Builds a new parser by applying the specified function to the result of this parser.
-
final
def
ne(arg0: AnyRef): Boolean
- Definition Classes
- AnyRef
-
final
def
notify(): Unit
- Definition Classes
- AnyRef
- Annotations
- @native()
-
final
def
notifyAll(): Unit
- Definition Classes
- AnyRef
- Annotations
- @native()
-
def
orElse[U >: T](p0: ⇒ Parser[U]): Parser[U]
Applies the specified parser when this parser fails.
Applies the specified parser when this parser fails.
a orElse b
succeeds if either of the parsers succeeds.In case both parsers fail, the
Failure
instance will be from the parser with the most successfully read characters. In the case of multiple failures having the same number of characters, the one with the highest precedence (this parser) will be chosen.Implementation note: The parameter is by-name to allow the definition of recursive parsers. In contrast to the former SDK parser combinators this is the only place where a parser with a by-name parameter is used whereas in all other places the additional cost is avoided.
-
def
parse(in: String): Parsed[T]
Parses the specified string and returns the result.
-
def
recoverWith[U >: T](pf: PartialFunction[Failure, Parser[U]]): Parser[U]
Handle certain errors, potentially recovering from it, by mapping them to a new parser that will be applied at the same starting position than the failing parser.
Handle certain errors, potentially recovering from it, by mapping them to a new parser that will be applied at the same starting position than the failing parser.
- See also
handleErrorWith to handle any/all errors.
-
def
rep(separator: String): Repeat[T]
Returns a parser that repeatedly applies this parser with the specified separator string between those invocations.
Returns a parser that repeatedly applies this parser with the specified separator string between those invocations.
p.rep(sep).min(1)
is equivalent to(p ~ (sep ~> p).rep).concat
.The returned parser offers an API to specify further constraints like
min
ormax
. -
def
rep(separator: Parser[Unit]): Repeat[T]
Returns a parser that repeatedly applies this parser with the specified separator parser between those invocations.
Returns a parser that repeatedly applies this parser with the specified separator parser between those invocations.
p.rep(sep).min(1)
is equivalent to(p ~ (sep ~> p).rep).concat
.The returned parser offers an API to specify further constraints like
min
ormax
. -
def
rep: Repeat[T]
Returns a parser that repeatedly applies this parser.
Returns a parser that repeatedly applies this parser. The returned parser offers an API to specify further constraints like
min
ormax
. -
def
repUntil[U](endCondition: Parser[U]): Parser[(List[T], Option[U])]
Returns a parser that repeatedly applies this parser until either this parser fails or the specified end condition is met.
Returns a parser that repeatedly applies this parser until either this parser fails or the specified end condition is met. The end condition will be applied after each successful invocation of this parser.
The result of the returned parser is a tuple consisting of the list containing the result of the invocations of this parser plus the result of the end condition. The latter is returned as an
Option
as it might be empty when the parsing finished because of this parser failing.Note that it is more convenient to include the end condition in the repeating parser itself and use the simpler
rep
method. This combinator is an alternative if you need to know the result of the end condition. -
def
repWith[U >: T](next: (U) ⇒ Parser[U]): Parser[List[U]]
Returns a parser that invokes the specified function repeatedly, passing the result of this parser if it succeeds, to produce new parsers that get applied until one of them fails.
Returns a parser that invokes the specified function repeatedly, passing the result of this parser if it succeeds, to produce new parsers that get applied until one of them fails.
The result of the returned parser is a list containing the result of this parser (if it succeeds) plus the results of successful invocations of the parsers returned by the specified function.
-
def
source: Parser[String]
Retrieves the part of the input consumed by this parser while discarding the result.
Retrieves the part of the input consumed by this parser while discarding the result.
This is useful in scenarios where many string-based parsers are combined and produce a deeply nested result like
String ~ Option[String] ~ List[String]
where it would require some boilerplate to concatenate the results. Using the source method, the entire text consumed by this combination of parsers will be returned.If you also need the position within the input or need to pass the result to a recursive parser manually, use the
cursor
method instead. -
final
def
synchronized[T0](arg0: ⇒ T0): T0
- Definition Classes
- AnyRef
-
def
toString(): String
- Definition Classes
- AnyRef → Any
-
def
void: Parser[Unit]
Discards the result of a successful parser.
-
final
def
wait(): Unit
- Definition Classes
- AnyRef
- Annotations
- @throws( ... )
-
final
def
wait(arg0: Long, arg1: Int): Unit
- Definition Classes
- AnyRef
- Annotations
- @throws( ... )
-
final
def
wait(arg0: Long): Unit
- Definition Classes
- AnyRef
- Annotations
- @throws( ... ) @native()
-
def
withCursor: Parser[(T, SourceFragment)]
Provides the result of this parser together with a cursor over the input, capturing the consumed source string and its position within the root input.
Provides the result of this parser together with a cursor over the input, capturing the consumed source string and its position within the root input. Use
cursor
if you do not need access to the actual result.This is required for parsers that create AST nodes that need to be resolved in a rewrite step and need to report the source location in case of failure. It is also required when passing a result of a first-pass parser to a recursive parser to preserve line positions.
-
def
withFailureMessage(msg: String): Parser[T]
Changes the failure message produced by a parser.
-
def
|(value: String)(implicit ev: <:<[T, String]): Parser[String]
Attempts to parse the specified literal string when this parser fails.
Attempts to parse the specified literal string when this parser fails.
a | b
succeeds if either of the parsers succeeds. -
def
|[U >: T](p: ⇒ Parser[U]): Parser[U]
Applies the specified parser when this parser fails.
Applies the specified parser when this parser fails.
a | b
succeeds if either of the parsers succeeds.Implementation note: The parameter is by-name to allow the definition of recursive parsers. In contrast to the former SDK parser combinators this is the only place where a parser with a by-name parameter is used whereas in all other places the additional cost is avoided.
-
def
~[U](p: Parser[U]): Parser[~[T, U]]
Applies the specified parser to the input left over by this parser and combines the two results.
Applies the specified parser to the input left over by this parser and combines the two results.
a ~ b
only succeeds if both parsers succeed, with the results in a wrapper class named~
for convenient pattern matching:a ~ b ~ c ^^ { case a ~ b ~ c => processResult(a, b, c) }
-
def
~(value: String): Parser[~[T, String]]
Attempts to parse the specified literal string from the input left over by this parser and combines the two results.
Attempts to parse the specified literal string from the input left over by this parser and combines the two results.
a ~ b
only succeeds if both parsers succeed, with the results in a wrapper class named~
for convenient pattern matching:a ~ b ~ c ^^ { case a ~ b ~ c => processResult(a, b, c) }
-
def
~>[U](p: Parser[U]): Parser[U]
Applies the specified parser to the input left over by this parser, but only keeps the right result.
Applies the specified parser to the input left over by this parser, but only keeps the right result.
a ~> b
only succeeds if both parsers succeed. -
def
~>(value: String): Parser[String]
Attempts to parse the specified literal string from the input left over by this parser, but only keeps the right result.
Attempts to parse the specified literal string from the input left over by this parser, but only keeps the right result.
a ~> b
only succeeds if both parsers succeed.